Rotary fluid pump



Feb. 6, 1968 w. DODSON 3,367,273

ROTARY FLUID PUMP Filed Feb. 15, 1966 WALTER oooso/v /4 INVENTOI? AT7'ORNEYS United States Patent C ABSTRACT 6F THE DISCLOSURE A rotaryfluid pump characterized by improved leak resistance having a housingproviding an inlet and an outlet, an impeller in the housing, poweredmeans connected to the impeller for driving the impeller to pump fluidfrom the inlet to the outlet and to produce relatively low and highpressure zones within the housing, the powered means communicatingbetween the exterior and interior of the housing only at the lowpressure zone and having provision for improved sealing at the point ofsuch communication, and a baflle mounted within the housing adjacent tothe inlet to minimize vortexing of fluid therein.

The present invention relates to a rotary fluid pump and moreparticularly to such a pump which is substantially leak proof so as tomaintain the area in which it is located free of unsightly, hazardousand wasteful leakage or accumulation from the pump and to avoid exposureof the pumped fluid.

During the production of wine in a winery, fluid pumps are employed totransfer the wine between the various production, fermenting and storagetanks prior to bottling. In order to maintain proper health standards,the areas in which the wine is produced must be maintained as clean andfree of waste material as possible. The conventional pumps presently inuse for this purpose are not able to operate for any protracted lengthof time without experiencing objectionable leakage. Such leakage isundesirable in that it is wasteful, violates the health laws, andconstitutes a serious safety hazard to workmen attending such productionequipment. The hazard is particularly acute in the pumping of highlyvolatile and combustible fluids, such as alcohol in brandy plants.

The conventional pumps usually employ an impeller housing having apowered impeller drive shaft extended therefrom with a packing type sealof felt or other similar material disposed in a pump housing around animpeller shaft which requires frequent replacement. Even at best, suchpacking material requires continuous adjustment and attention tomaintain even minimum operating standards. In order properly to operate,a minimal amount of leakage of fluid is permitted through the packingwhich serves to lubricate the packing material. Consequently, if thepacking is adjusted to have a sufficiently tight contact with theimpeller drive shaft to prevent such minimal leakage, the packingmaterial burns, causing disintegration and collapse of the seal. For thesame reason, conventional packing type seals cannot be employed wherethe pump may run dry for any extended period. Furthermore, sealsprovided with an external lubricant supply have not been employed inthis environment because of the danger of fluid contamination uponfailure of the seal and intermixing of the fluid with the lubricant.

The difficulty in providing an effective seal in such conventional pumpsis due in a substantial degree to the arrangement of the impeller driveshaft with respect to a high pressure impeller chamber within the pumphousing. In these pumps, the shaft is extended through a wall of thepump housing immediately adjacent to the high pressure impeller chamber.This necessitates the use of a seal or packing unit in the wall aroundthe shaft to prevent leakage at a position of maximum pressure exposure.

3,367,273 Patented Feb. 6, 1968 Since the high pressure fluid iscontinually directed against the seal, if not properly and frequentlyadjusted, it soon permits excessive leakage along the shaft outwardly ofthe pump housing. It was recognized, therefore, in developing theimproved pump of the present invention that such leakage could be bettercontrolled if the powered impeller shaft were extended into the housingfrom the low pressure or suction end of the pump only. In sucharrangement, the high pressure end of the housing can be completelyclosed except for the discharge outlet therefrom without the need for aseal in such a vulnerable location.

Accordingly, it is an object of the present invention to provide animproved rotary fluid pump which is capable of operating for extendedperiods without fluid leakage.

Another object is to provide such an improved rotary fluid pump whichhas a housing completely closed at its positions of highest internalpressure.

Another object is to provide a rotary fluid pump of the characterdescribed which extends a powered impeller drive shaft into its housingin optimum location for effective sealing.

Another object is to provide a rotary fluid pump having a housing whichadmits an impeller drive shaft at the low pressure or suction end of thehousing.

Another object is to provide a rotary fluid pump capable of providingfluid tight integrity with a minimum of attention, adjustments andre-packing.

Another object is to provide a rotary fluid pump having a housingcapable of effectively utilizing a mechanical seal about an impellerdrive shaft.

Another object is to provide a rotary fluid pump having a poweredimpeller drive shaft extended therein which has a replaceable peripheralwear surface for engagement with the seal.

Another object is to provide a rotary fluid pump capable of utilizing anexternal lubricant supply for a mechanical seal thereof about a driveshaft.

Other objects and advantages of the present invention will subsequentlybecome more clearly apparent upon reference to the following descriptionand accompanying drawing.

In the drawing:

FIG. 1 is a side elevation of a rotary fluid pump embodying theprinciples of the present invention disposed in operating connectionwith a drive motor and mounted on a common base.

FIG. 2 is a somewhat enlarged central longitudinal section through thepump of FIG. 1.

FIG. 3 is a somewhat enlarged transverse vertical section through animpeller compartment and discharged opening of the pump taken generallyon line 3-3 of FIG. 2.

Referring more particularly to the drawing, a rotary fluid pumpembodying the principles of the present invention is generally indicatedby the numeral 10. As best shown in FIG. 1, the pump is adapted to bemounted on a base 11 by a plurality of anchor bolts, one of which isshown at 12 extended through a flange 14 of the pump and screwthreadably received within the base. An electric motor 18 is similarlymounted on the base by a plurality of anchor bolts 19 extended throughcorresponding support feet 20 on the motor and screw threadably receivedwithin the base. An elongated drive shaft 22 is extended from the motorand into the pump 10'.

The pump 10 provides a housing 25 which includes a generally circularhigh pressure discharge or outlet end 26. The pump housing furtherincludes an elongated, some what smaller diameter, suction or inlet end28 providing an annular flange 29 secured to the discharge end 26 by aplurality of cap screws 30 extended through the flange 3 in screwthreading engagement with screw threaded bores 31 in the discharge endof the housing.

The discharge end 26 of the pump housing provides a completelyunobstructed end wall 32 and an integral substantially circular sidewall 34 having an inner annular surface 35 circumscribing and enclosingan impeller compartment 37. The side Wall further includes an integral,radially outwardly extended outlet conduit circumscribing a dischargepassage 42 communicated with the impeller compartment 37 The outletconduit includes an outer end 43 which is connectable with any suitablefluid directing conduit, not shown.

The inlet end 28 of the pump housing 25 provides a side wall 46 havingan annular inner surface 47. The inlet end further includes an end wall48 which combines with the side wall to enclose and circumscribe a fluidsuction chamber 50 communicated with the impeller compartment 37 of thedischarge end 26 0f the housing. An annular boss or protuberance 52 isaxially outwardly extended from the end wall 48 in concentric relationwith the side wall 46. An annular recess 54 is formed in the boss and isclosed by an annular end plate 55 removably mounted on the boss by aplurality of cap screws 57. An elongated fluid inlet tube is radiallyextended through the side wall 46 and provides an inner end 62 inwardlyspaced from the side wall and an opposite outer end 64 extended from thewall for connection to a fluid supply conduit, not shown. An elongatedflat substantially rectangular baflle plate 66 is secured to the innersurface 47 of the side wall 46 closely adjacent to the inner end 62 ofthe fluid inlet tube 60.

A motor drive shaft 22 is extended into the pump housing 25 inconcentric relation to the side walls 46 and 34 of the housing. Thedrive shaft provides a reduced diameter screw threaded end portion 70extended into the impeller compartment 37 of the discharge end 26 of thehousing. The screw threaded end of the drive shaft affords a shoulder 72and has an elongated longitudinally extended key way 73. An impeller hub75 is slidably mounted on the screw threaded end of the drive shaft andis constrained thereon for rotation with the drive shaft by an elongatedkey 76 disposed in the key Way 73. The hub is axially constrained insuch position by a lock nut 77 screw threadably received on the end ofthe drive shaft tightly to clamp the hub against the shoulder 72.

As best shown in FIGS. 2 and 3, a pair of arcuate centrifugal typeimpeller blades or vanes 80 are mounted in diametrically opposedrelation on the hub 75 for rotary movement within the impellercompartment 37 by a plurality of cap screws 82. The blades include outerends 84 which are individually disposed in closely spaced relation tothe inner annular surface 35 of the side wall 34. A pair of helicalfluid supply blades are mounted on the hub 75 for rotation with thedrive shaft 70 within the suction chamber 50. The supply blades aresecured to the hub as by Welding or the like or may be formed integrallytherewith, as desired.

An elongated tubular sleeve 92 is disposed about the drive shaft 70 andprovides an inner end 94 which has a notch 95. The notch receives aprotuberance or integral dog 96 on the impeller hub 75 to provide adriving connection there-between for rotation of the sleeve with thedrive shaft. A pair of mechanical seals 100 are disposed within theannular recess 54 of the boss 52. Each of the seals includes an annularsealing ring 102 which is held in sliding, sealing engagement againstthe outer periphery of the sleeve 92 by an annular coiled spring 104.The seals are disposed in axially spaced relation to form therebetwee anannular lubricant compartment 106 within the recess. A radially extendedlubricant supply passage 108 is formed in the boss 52 and is providedwith a suitable fitting 110 for directing lubricant into the compartment106.

4 OPERATION The operation of the described embodiment of the subjectinvention is believed to be clearly apparent and is briefly summarizedat this point. Prior to operation, the lubricant compartment 106 isfilled with a suitable grease or other lubricating material underpressure through the fitting 110. Such lubricating material completelyencircles the periphery of the sleeve 92 about the motor drive shaft 70which, in combination with the springs 104, tends to urge the seal rings102 into sealing engagement with the periphery of the sleeve. With thissealing arrangement, it is readily apparent that the pump 10 can beoperated dry without any adverse effect upon the seals 100.

When the inlet tube 60 is connected to a source of fluid, the motor 18is energized to cause rotation of the pump impellers 80 and 90, in acounterclockwise direction, as viewed in FIG. 3. Such rotation of theimpellers produces a low pressure or suction Within the suction chamber50 to draw such fluid inwardly of the pump housing through the inlettube 60. Ordinarily, the entrance of such fluid into the housing wouldtend to swirl and create an undesirable vortex within the suctionchamber before being drawn axially through the helical supply blades 90into the discharge end 26 of the housing. Such swirling effect isprevented by the baflle plate 66 which effectively breaks up andprecludes the formation of a vortex. This maintains the suction chamberat a sufhciently low pressure to preclude cavitation and any adverseeffect upon the seals 100.

With continued rotation of the drive shaft 70, the helical fluid supplyblades 90 force the fluid within the suction chamber 50 axially into theimpeller compartment 37. The fluid is then picked up by the inner endsof the impeller blades 80 for centrifugal discharge radially outwardlythrough the discharge passage 42 of the outlet conduit 41 During suchpumping action of the impeller blades 80, a small amount of fluid ispermitted to bypass each of the blades between their outer ends 84 whichmaintains the blades in self-centering relation within the compartment37. Consequently, a bearing and seal structure is not required in theend wall 32 of the housing to support the end of the drive shaft 70.

The sleeve 92 on the drive shaft 70 is concurrently rotated therewiththrough the meshing relation between the protuberance 96 on the impellerhub 75 and the notch in the sleeve. As previously described, theperiphery of the sleeve provides a wear surface for the seal rings whichsleeve can be easily and quickly replaced when such wear occurs withoutreplacing the motor drive shaft. It is readily apparent that the sleevebe provided with a notch 95 at each end so that the sleeve can be merelyreversed to present a new wear surface for the seals 100. It is notedthat the seals are continually lubricated by lubrication in the annularcompartment 106 which enables the pump to operate dry without anyadverse effect upon the seals.

In view of the foregoing, it is readily apparent that the structure ofthe present invention provides an improved rotary fluid pump for pumpingfluids such as wine, alcohol and the like, without contaminating suchfluid and with virtually no leakage of the fluid from the pump. Thestructure, by its novel drive arrangement, is able to utilize amechanical seal which has an external lubricant supply so as not to beadversely affected by running the pump dry. A low pressure area ismaintained Within the pump housing adjacent to the seals which minimizesthe internal pressure tending to force fluid through the seals.Furthermore, the pump impellers are entirely supported on the motordrive shaft and do not require the usual support bearings and seals inthe high pressure end of the housing as in conventional pump structures.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom Within the scope of theinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent devices and apparatus.

Having described my invention, what I claim as new an-d desire to secureby Letters Patent is:

1. A rotary fluid pump comprising a housing having a high pressureoutlet end and an opposite relatively low pressure inlet end, impellermeans disposed Within said housing, a drive shaft mounting said impellermeans for rotation within the housing and extended through said low:pressure inlet end of the housing, an elongated tubular sleevereleasably mounted on said shaft for rotation therewith providing areadily replaceable peripheral Wear surface, a seal disposed in theinlet end of the housing in circu-mscribing relation to the shaft andengaged with the peripheral wear surface of the sleeve, the outlet endof the housing providing an uninterrupted end wall to preclude leakagehaving a circular impeller compartment providing a discharge orifice,the inlet end of the housing having a suction chamber communicating withthe impeller compartment and having fluid supply means connected to saidsuction chamber, the impeller means including a centrifugal impellerdisposed for rotation within the impeller compartment on the drive shaftand an axial flow impeller on the drive shaft disposed closely adjacentto the centrifugal impeller within the suction chamber for impellingfluid from the suction chamber axially into the centrifugal impeller,and a baflle plate secured to the housing at the inlet end within thesuction chamber disposed to minimize the development of a fluid vortexWithin the suction chamber.

2. The rotary fluid pump of claim 1 in which said h-ousing includes aninternal annular recess at said inlet end; and said seal comprises apair of annular seal rings mounted in axially spaced relation withinsaid recess in the housing and having resiliently flexible innerperipheral portions circumscribing said sleeve on the drive shaft insliding sealing relation, said seal rings providing therebetween anannular lubricant passage; and means mounted on the housing to supplylubricant to said passage.

3. A rotary fluid pump comprising a housing having an outlet end and anopposite inlet end, impeller means disposed within said housing, a driveshaft mounting said impeller means for rotation Within the housing andextended through said inlet end of the housing, a seal disposed in theinlet end of the housing in circumscribing relation to the shaft, theoutlet end of the housing providing an uninterrupted end Wall topreclude leakage therefrom having a circular impeller compartmentproviding a discharge orifice, the inlet end of the housing having asubstantally cylindrical suction chamber communicating with the impellercompartment and adapted to have fluid supply means connected to saidsuction chamber, the impeller means including a centrifugal impellerdisposed for rotation Within the impeller compartment on the drive shaftand an axial flow impeller on the drive shaft disposed within thesuction chamber for impelling fluid from the suction chamber axiallyinto the centrifugal impeller, and a baffle plate mounted within thesuction chamber and extended substantially radially therein to minimizethe development of a fluid vortex within said suction chamber.

References Cited UNITED STATES PATENTS 809,653 1/1906 Ward 230-127971,850 10/1910 Krogh 103-103 1,931,724 10/1933 Fageol et al. 103-1032,013,078 9/1935 Slocum 103-88 2,348,246 5/1944 Dixon 103-103 2,385,7309/1945 Read 103-103 2,853,018 9/1958 Stark 103-103 3,079,865 3/1963 Lipeet al. 103-103 3,196,799 7/1965 Loss 103-109 FOREIGN PATENTS 1,249,64211/ 1960 France.

HENRY F. RADUAZO, Primary Examiner.

